Sticking sprue plate ?

[Tedly]

I got a new to me Lyman # 358495 mold and it seems like as it heats up and starts to cast well , the sprue plate gets tighter and tighter....is this normal ? I backed off the screw , and sprue plate operation is more free it seems OK ...is it normal to need to back off the sprue plate ?

[Mike W1]

I've always set the sprue plate to swing freely when cold and find it necessary to readjust a bit when the mould gets up to casting temperature. So I'd say it's normal as all mine act that way.

[country gent]

Tedly, As metals heat they expand and joints get tighter.As the blocks heat they expand as the sprue plate heats it gets thickeras the shoulder bolt heats it expands. Setting it while hot is where it needs to be. Pre heating on a hot plate to temps keeps it close to the same from start to finish of a casting session. Another to help is to very lightly lube the sprue plate joint and plate with a very light coat of 2 cycle motor oil AC oil or other high temp lube. WIpe a thin coat on with a q-tip then remove excess with dry end on bottom of plate and tops of blocks. ANother pointer is to put a piece of lead or copper wire under the sprue plate scre set screw to help give it better grip to hold the screw.